How to respond when you're nicely discussing your mother's care with your sister and your sister out of the blue tells you to go to hell?

Grace, they probably put your sister down a s the point of contact because she was the one who brought your mother in after the stroke. If your mother is legally competent, she should be able to change that to you.

Don’t forget snail mail, cards etc. I’ve lived for 20 years on an isolated farm with no mobile reception and a dodgy landline (often when it rains, the electric fences short out the phone lines). I’ve often had to rely on the post, and it still works well!

There's no landline in her room, or at the desk?

Why aren't you discussing discharge dates and care plans with your mother?

“When we’re together, it’s as if I’m already there.”

Said with a slight head tilt, eye contact, a sing-song voice and small, tight smile.

https://www.agingcare.com/questions/family-members-angry-at-information-sharing-regarding-options-for-mothers-care-474321.htm

Sorry, but you seem to have been having problems with sister since Mom has had this stroke. And you continue to talk to her about Moms health issues. I am pretty sure that you were told to shut up by her in one of your prior messages. Why do you keep trying to talk to these people? If Mom is competent, than the choice is hers. Doesn't matter a fig what the rest of you think. Seems like Uncle may influence her decision. The doctors should go with what Mom wants or needs. None of you live near enough or with 2 of u in touch with her enough to make decisions for her. Why do you keep on about it. I would have backed off days ago. I have a SIL like this, she is never interested in what I have to say so I don't say anything.

The last time I was in the same physical space as my sister was about 5 years ago and it was at a wedding. Our estrangement goes back over 20 years and I've had similar encounters with my sister that you have had. I would encourage you to stop being civil to her. When my sister became irrational with me I refused to speak till she understood that I was *Not* going to allow her to speak to me like I was dirt. Next time she says "go to hell". I would suggest something like.
"I can't go I've got to take care of our mother"
"You first, since it's age before beauty"
"Hell might be more restful then taking care of mother"
"If I go to hell then who's going to take care of mother, certainly not you"

I would follow this up with "When you decide to stop talking to me like I'm the a****** I will listen to you and not before, I'm taking care of mother NOT you and we are deciding the best care for her, not you. If you can't be civil to me then don't speak to me at all."

Some times standing up to people is the best course of action.

When a parent is serious ill, children go bonkers. Family crisis erupts. It happens in every family.

Tell your sister that you expect to have adult, respectful conversations, and if she tells you that again (or has any similar outbursts), go no-contact with her. She's not worth the angst, stress or not. You both have stress about your mom.

Do you or she have power of attorney for your mom and are making any decisions for her? That's the person with the power, and the other sibling needs to keep the peace in order to stay in the loop.

First why do you even care what your sister says or thinks? You're the one that's stepping up to make sure your mom has things in place for when she comes home, and staying with her for 3 weeks, so just proceed with what has to be done, and tune out your sister.
This is a stressful time for both of you, as I'm sure you both want what's best for your mom, so let her know if she can't respect what you have to say and talk to you with respect, that you won't waste your time talking with her anymore.

She tells you to go to hell:

”Fine, I’ll save you a seat.”

If you haven't had a relationship with your 21 years older sister throughout your life, why are you expecting one now? Since you are the one planning to spend 3 weeks with your mother post rehab, what difference does it make what your sister thinks about her care anyway? Block her on your phone, if necessary, and focus on caring for mom after she's released, however YOU see fit. If sissy wants to know why she's blocked, tell her: You told me to go to hell so I figured we were done communicating. And we ARE! You're blocked.

Good luck!

.

Is this behavior terribly unusual for your Sister?
Have you, under normal circumstances, got along really well?
This behavior, as you describe it, of your being very nice, and your sister telling you to "go to hell" is extreme, and I would say unusual. I would ask her if you have unbeknownst to yourself, offended her, or if she is upset because Mom has been ill.
You are correct, that speaking with someone who is exhibiting extremely odd behavior suddenly, and for utterly no reason, isn't probably able right now to discuss things with you. You should back away a bit.
Might I ask you if EITHER you or your Sister live with your Mother?
Do you have a difference of opinion as to whether/or how much care your Mom needs now?
You describe your Mom as cognitively capable. Is she having physical deficits that might be a source of worry to either you or Sister? Is sister expressing herself stressed at the moment by other family, health, work issues?
Illness is always a source of worry and distress in family. We are all individuals and our reactions all differ. And of course, Sister's current stress level may have zero to do with you or with Mom. In most cases where we feel someone is reacting because of us, it has little to do with us.
Anything we say here, with so little description of what is going on, is, of course, pure guesswork. But, unless Sister is diagnosed with mental disorders, this behavior is unusual and worthy of deep thought on your part.

Go no contact with her, she is not respecting you or your opinion(s)
For every bad action, there is a bad reaction, set your boundaries and stick with them.

We teach people how to treat us, she seems to know that you will take her verbal abuse, and with that knowledge it will continue and most likely get worse.

The ball is in your court.

Sorry about this.

Has your sister always been difficult or hard to get along with? Are your and your sister’s caregiving contributions equal in terms of time and effort or is there a difference causing some resentment there?